Sextus Empiricus: Logic 341
or vice versa], he will fall into circular reasoning. But if he makes a stand
somewhere, either he will say that the cause is established as far as what
was previously said is concerned, in which case he introduces relativity
and abolishes the [grounding in] nature [i.e., reality], or he is taking
something as an hypothesis, in which case he will be stopped. It is
therefore perhaps also possible by means of these modes to confute the
rashness of the dogmatists in their causal explanations.
Logic
Sextus PH 2.48-79 [III-38]
Ch. vi Concerning the Criterion 'By Means of Which'
- The disagreements that have arisen among the dogmatists regarding
this [criterion] are many, even unlimited. We, however, in view of a
systematic treatment, say that since, according to them, man is that 'by
whom' matters are judged, a man would have nothing by means of which
he will be able to judge (as they themselves agree) unless it is sense-
perception and intellect. So, if we shall show that he is not able to judge
matters either by means of sense-perception alone or intellect alone or
both, we shall have addressed summarily all their particular opinions,
for they all seem to make references to these three positions. 49. Let us
begin with the senses.
Since, then, some say the senses have "groundless experiences," for
nothing they seem to grasp exists, whereas others say that all the things
that are thought to stimulate the senses exist, and still others say that
some of these exist and some do not, we shall not [be able to] know to
whom to give assent. For we can neither decide the disagreement by
means of sense-perception, since it is regarding the senses that we are
investigating whether they have groundless experiences or whether they
truly grasp, nor by means of anything else, since there is no other criterion
by means of which one should judge things according to the present
hypothesis. 50. Therefore, it will be undecidable and ungraspable whether
sense-perception has groundless experiences or grasps something, to
which is added the conclusion that, in the judgement about those things,
we ought not to attend to sensation alone, regarding which we are not
in a position to say if it grasps anything [at all] in the first place. - But let us grant for the sake of argument that the senses are
capable of grasping. Still, granted this, they will be found to be no less
untrustworthy in relation to the judgement of objects external to them.
At any rate, the senses are stimulated variously by external objects. For